Currently, there are two approaches for estimating a number of objects, such as reinforcement steel bars. The first approach is to count the objects one by one by way of manual counting. Drawbacks to the first approach are that considerable labor cost may be incurred, and that counting errors are more likely to be made when there is a huge quantity of the objects. Moreover, manual counting is very time-consuming.
The second approach is counting by weighing, in which a single one of the objects and the whole batch of the objects are respectively weighed, and the weight of the whole batch of the objects is then divided by the weight of the single one of the objects so as to obtain the number of the objects. However, the accuracy of counting by weighing only ranges between 93% and 95%. Furthermore, in order to weigh the objects, the burden of repeatedly moving the objects is inevitable and causes inconvenience in performing the second approach.
In this way, a more convenient, accurate and cost-saving approach for estimating a number of objects is desired.